Japanese Red Maple Trees

Japan has a long history of cultivating Maple trees, and horticulturists have produced many different varieties, not only in Japan but also in Korea and China. In the eighteenth century a doctor-botanist, Carl Thunberg from Sweden brought out of Japan drawings of maple trees, that he saw on his travels there.

By 1828 the first specimen was brought to England, and was named acer palmatum because of the resemblance of the shape of the leaf to that of a human hand.

There are hundreds of cultivars of acer palmatum, each of which has been selected for specific desirable characteristics, such as colour and form of the flower, disease resistance etc. A very popular variety is Acer Palmatum ‘Bloodgood’. Like all Japanese maples, this is a deciduous tree. A Bloodgood has very deep red leaves which turn bright red in the autumn(fall), making a very striking display. The redleaf maples are the most popular varieties, and as well as the Bloodgood, they include the Atropurpureum, Crimson Queen, and others.

Growing Conditions of Japanese Maple

Depending on type, the height of a mature Japanese maple can be anywhere from 0.5m to 25m, although Bloodgoods tend to reach about 6m in height. Some of the cultivars like shade but many prefer to be in full sun, as indeed the Bloodgood does. Bloodgoods will not grow well in clay soil, or soil that is heavily alkaline, preferring relatively neutral conditions. Prior to planting the soil should be prepared with mulch, and fertiliser. In the spring, before leaves appear the Bloodgood should be fertilised regularly.

Pruning of Japanese Red Maples

It is not essential to prune Japanese Red Maple trees, but this is often done to shape them artistically. These points should be used as a guide to pruning:

• Pruning should start only after the roots are established, which is usually two or three years after planting.
• For very small branches, prune before sap flows during spring, but after the leaves are fully out. Prune the larger branches during dormancy.
• Prune the limbs when as small as possible.
• Prune small limbs just beyond a pair of buds, but large branches just outside the bark ridges.
• After pruning let the exposed wood dry naturally.

Japanese Red Maple Bonsai Trees

Some of the Japanese red maple cultivars are suitable for growing as bonsai trees. In common with many bonsai trees, the maple bonsai can be grown either indoors or outdoors. Pruning of the branches should be done during the dormant phase, after the leaves have been shed for winter.

For further information on the changes of leaf colours, see Why Do Leaves Change Colours?

Reference:

Japanese Maples: The Complete Guide to Selection and Cultivation, Fourth Edition

Timber Press, May 2010 Peter Gregory, J.D. Vertrees